81015427200 has 384 divisors, whose sum is σ = 271716984000. Its totient is φ = 21213757440.

The previous prime is 81015427193. The next prime is 81015427201. The reversal of 81015427200 is 272451018.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81015427201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 145449322 + ... + 145449878.

Almost surely, 2^81015427200 is an apocalyptic number.

81015427200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81015427200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135858492000).

81015427200 is an abundant number, since it is smaller than the sum of its proper divisors (190701556800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81015427200 is a wasteful number, since it uses less digits than its factorization.

81015427200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

Adding to 81015427200 its reverse (272451018), we get a palindrome (81287878218).

The spelling of 81015427200 in words is "eighty-one billion, fifteen million, four hundred twenty-seven thousand, two hundred".